Ranking Domains Using Domain Maturity

ABSTRACT

Ranking domains for search engines is provided herein. To rank a domain, contributing domains associated with the domain are identified. Additionally, the maturity of each of the contributing domains is determined. A rank for the domain is then determined based at least in part on the maturity of each of the contributing domains. The domain rankings may then be used to order results for search queries.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

Domain ranking is frequently used by search engines to facilitate theordering of results for a search query. In general, a domain may beranked based in part on the number of contributing domains associatedwith that domain. A contributing domain may be, for instance, one thatincludes a link to the domain being ranked. For example, if hundreds ofother domains that maintain at least one web site include one or morelinks to a particular domain, the domain may receive a higher rank thananother domain that is referenced by just a few other domains. Inaddition to the number of contributing domains, ranks of thecontributing domains may influence the rank for the domain as well. Forexample, if a trusted, popular domain, such as Yahoo.com or CNN.com,includes a link to the domain, the ranks for such popular domains may beattributed to the rank for the domain. Receiving a higher domain rankingoften means that the domain would be listed above other competingdomains, thereby affording more visits by those browsing or searchingthe Internet. For domains that maintain commercial web sites or websites that charge advertisers on per-click or per-visit basis, a higherdomain ranking means better profitability. For example, sites likeYahoo.com and CNN.com, which are visited by millions of people each day,attract many commercial advertisers who are willing to pay large fees.

Typically, a domain includes links to other domains to make its contentmore useful and attractive for its visitors. Most existing domainranking algorithms often assume that a number of contributing domainsthat maintain one or more links to a particular domain provides anindication of the popularity or utility of the particular domain. Thosealgorithms also tend to assume that the particular domain is popularand/or useful if a link is included in another domain that is well-knownfor its popularity and utility, such as MSN.com. These assumptions havebeen held to be mostly correct when it was neither easy nor cheap toregister and maintain a domain.

Due in part to increased competition in the domain registration marketin recent years, however, the cost involved in purchasing a domain hasdecreased significantly. In some cases, domain registrars even offerfree domain registrations for up to thirty to sixty day trial periods.Spammers often take advantage of such offers through a spam techniqueknown as a web farm. In particular, spammers purchase or otherwiseobtain a large number of sites and interlink the sites together toincrease the sites' rankings by artificially increasing the number ofcontributing domains for some or all of the sites. In effect, thispractice defeats the assumption that the more a domain is referenced byother domains, the more likely that the domains is popular and/or usefulsuch that it should be highly ranked.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

Embodiments of the present invention relate to, among other things,ranking a domain. One or more contributing domains associated with atarget domain are identified and the maturity of the contributingdomains is determined. By way of example only and not limitation, thematurity of a contributing domain may be determined based on the datethat it was registered or the date that it was first discovered by asearch engine. A rank for the target domain is then calculated based onthe maturity of the contributing domains associated with that targetdomain. Accordingly, when a search engine receives a search query,results may be ordered based at least in part on the domain rankings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The present invention is described in detail below with reference to theattached drawing figures, wherein:

FIG. 1 is a block diagram of an exemplary computing environment suitablefor use in implementing the present invention;

FIG. 2 is a block diagram of an exemplary system in which embodiments ofthe present invention may be employed;

FIG. 3 is a block diagram of an exemplary search engine in accordancewith an embodiment of the present invention;

FIG. 4 is a flow diagram showing a method for ranking a domain inaccordance with an embodiment of the present invention; and

FIG. 5. is a flow diagram showing a method for presenting search resultsin accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

The subject matter of the present invention is described withspecificity herein to meet statutory requirements. However, thedescription itself is not intended to limit the scope of this patent.Rather, the inventors have contemplated that the claimed subject mattermight also be embodied in other ways, to include different steps orcombinations of steps similar to the ones described in this document, inconjunction with other present or future technologies. Moreover,although the terms “step” and/or “block” may be used herein to connotedifferent elements of methods employed, the terms should not beinterpreted as implying any particular order among or between varioussteps herein disclosed unless and except when the order of individualsteps is explicitly described.

Overview

Embodiments of the present invention provide an approach for ranking adomain based on the maturity of contributing domains associated with thedomain. By way of example only and not limitation, a maturity of acontributing domain may be based on the date that the contributingdomain was registered or the date that the contributing domain was firstdiscovered by a search engine.

Less mature (i.e., newer) domains typically have a higher likelihood ofbeing spam and/or being a part of a web farm that attempts toartificially inflate domain rankings for domains in the web farm.Accordingly, by taking into account the maturity of contributing domainswhen determining a rank for a domain, embodiments of the presentinvention provide domain rankings in which more relevant and usefuldomains may be ranked higher than spam domains and/or less relevantdomains.

Accordingly, in one aspect, an embodiment of the present invention isdirected to a method for ranking a domain. The method includes receivinga list of one or more contributing domains associated with the domain.The method also includes determining a maturity for at least one of thecontributing domains. The method further includes calculating a rank forthe domain based at least in part on the maturity for the contributingdomain.

In another aspect of the invention, an embodiment is directed to amethod for presenting search results. The method includes receivinginformation associated with a number of domains. The method alsoincludes determining a maturity for each of one or more contributingdomains associated with each domain. The method further includescalculating a rank for each of the domains based at least in part on thematurity for the contributing domains associated with the each domain.The method also includes generating one or more search results thatinclude domains that match a search query. The method still furtherincludes presenting the search results in accordance with ranks of thedomains that match the search query.

In a further aspect, an embodiment of the present invention is directedto a search engine for ranking search results. The search engineincludes a ranking component configured to determine one or morecontributing domains associated with each of a number of domains. Theranking component is also configured to determine a maturity for each ofthe contributing domains and to calculate a rank for each of the domainsbased at least in part on the maturity for at least one of thecontributing domains. The search engine also includes a searchingcomponent configured to perform a search in response to a search queryand to return one or more search results comprising at least one of thedomains that match the search query.

Exemplary Operating Environment

Referring to the drawings in general and initially to FIG. 1 inparticular, an exemplary operating environment for implementingembodiments of the present invention is shown and designated generallyas computing device 100. Computing device 100 is but one example of asuitable computing environment and is not intended to suggest anylimitation as to the scope of use or functionality of the invention.Neither should the computing device 100 be interpreted as having anydependency or requirement relating to any one or combination ofcomponents illustrated.

The invention may be described in the general context of computer codeor machine-useable instructions, including computer-executableinstructions such as program modules, being executed by a computer orother machine, such as a personal data assistant or other handhelddevice. Generally, program modules including routines, programs,objects, components, data structures, etc., refer to code that performparticular tasks or implement particular abstract data types. Theinvention may be practiced in a variety of system configurations,including hand-held devices, consumer electronics, general-purposecomputers, more specialty computing devices, etc. The invention may alsobe practiced in distributed computing environments where tasks areperformed by remote-processing devices that are linked through acommunications network.

Computing device 100 includes a bus 110 that directly or indirectlycouples the following devices: memory 112, one or more processors 114,one or more presentation components 116, input/output (I/O) ports 118,I/O components 120, and an illustrative power supply 122. Bus 110represents what may be one or more busses (such as an address bus, databus, or combination thereof). Although the various blocks of FIG. 1 areshown with lines for the sake of clarity, in reality, delineatingvarious components is not so clear, and metaphorically, the lines wouldmore accurately be grey and fuzzy. For example, one may consider apresentation component such as a display device to be an I/O component.Also, processors have memory. We recognize that such is the nature ofthe art, and reiterate that the diagram of FIG. 1 is merely illustrativeof an exemplary computing device that can be used in connection with oneor more embodiments of the present invention. Distinction is not madebetween such categories as “workstation,” “server,” “laptop,” “hand-helddevice,” etc., as all are contemplated within the scope of FIG. 1 andreference to “computing device.”

Computing device 100 typically includes a variety of computer-readablemedia. By way of example, and not limitation, computer-readable mediamay comprises Random Access Memory (RAM); Read Only Memory (ROM);Electronically Erasable Programmable Read Only Memory (EEPROM); flashmemory or other memory technologies; CDROM, digital versatile disks(DVD) or other optical or holographic media; magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,carrier wave, or any other medium that can be used to encode desiredinformation and be accessed by computing device 100.

Memory 112 includes computer-storage media in the form of volatileand/or nonvolatile memory. The memory may be removable, nonremovable, ora combination thereof. Exemplary hardware devices include solid-statememory, hard drives, optical-disc drives, etc. Computing device 100includes one or more processors that read data from various entitiessuch as memory 112 or I/O components 120. Presentation component(s) 116present data indications to a user or other device. Exemplarypresentation components include a display device, speaker, printingcomponent, vibrating component, etc.

I/O port(s) 118 allow computing device 100 to be logically coupled toother devices including I/O components 120, some of which may be builtin. Illustrative components include a microphone, joystick, game pad,satellite dish, scanner, printer, wireless device, etc.

Exemplary System

Referring now to FIG. 2, a block diagram is provided illustrating anexemplary system 200 in which embodiments of the present invention maybe employed. It should be understood that this and other arrangementsdescribed herein are set forth only as examples. Other arrangements andelements (e.g., machines, interfaces, functions, orders, and groupingsof functions, etc.) can be used in addition to or instead of thoseshown, and some elements may be omitted altogether. Further, many of theelements described herein are functional entities that may beimplemented as discrete or distributed components or in conjunction withother components, and in any suitable combination and location. Variousfunctions described herein as being performed by one or more entitiesmay be carried out by hardware, firmware, and/or software. For instance,various functions may be carried out by a processor executinginstructions stored in memory.

Among other components not shown, the system 200 may include multipleclient devices, such as client device 202, multiple source devices, suchas source device 204, and a search engine 208. Each of the clientdevices, source devices, and search engine may be any type of computingdevice, such as computing device 100 described with reference to FIG. 1,for example. The components may communicate with each other via anetwork 206, which may include, without limitation, one or more localarea networks (LANs) and/or wide area networks (WANs). Such networkingenvironments are commonplace in offices, enterprise-wide computernetworks, intranets, and the Internet. It should be understood that anynumber of client devices, source devices, search engines, and networksmay be employed within system 200 within the scope of the presentinvention.

Source devices, such as the source device 204, may maintain a variety ofdomains. For example, the source device 204 may be a web server thatmaintains multiple domains. The search engine 208 may access domaininformation by communicating with these source devices. For example, thesearch engine 208 may periodically crawl the source device 204 to accessand/or update domain information, such as domain registration date,domain expiration date, domain swapping date(s), and a set of linkeddomains.

The search engine 208 accesses domain information from the multitude ofsource devices, such as the source device 204, and determines a rank foreach of the domains maintained by the source devices. The ranks may beused to sort the domains when users access the search engine 208 tosearch for particular domains through the client device 202.

Referring now to FIG. 3, an exemplary search engine 300 in accordancewith an embodiment of the present invention will be described in furtherdetail. Among other components not shown, the search engine may includea searching component 302, a ranking component 304, a database 308, anda user interface component 306. Each component may comprise a program,routine, application, or other machine-executable code capable ofperforming the actions discussed herein. One skilled in the art willrecognize that the components shown in FIG. 3 are provided forillustrative purposes only and other arrangements may be provided inaccordance with various embodiments of the present invention.

Generally, the search engine 300 may receive search queries from clientdevices, such as the client device 202 of FIG. 2, via the user interfacecomponent 306. The user interface component 306 may communicate toreceive search queries from client devices and pass the search queriesto the searching component 302 for performing searches. The userinterface component 306 may also communicate to receive search resultsfrom the searching component 302 and return the search results to theclient devices.

The searching component 302 may receive a search query from the userinterface component 306 and perform a search to generate search resultscomprising domains stored in the database 308 that match the searchquery in accordance with the ranks of the domains. The searchingcomponent 302 may also return the search results to the user interfacecomponent 306, which may generate a search results user interface andprovide the search results user interface to the requesting clientdevice.

The ranking component 304 may collect information associated withvarious domains from one or more source devices, such as the sourcedevice 204 of FIG. 2, by, for example, crawling the source devices. Theranking component 304 may determine contributing domains associated witheach domain, determine a maturity for each of the contributing domains,and calculate a rank for each domain based on the maturity of thecontributing domains associated with a respective domain. In someembodiments, the ranking component 304 may also save domain informationand domain ranks in the database 308. In some embodiments, the maturityof a contributing domain is determined based on the date that thecontributing domain was registered or the date that the contributingdomain was first discovered by a search engine (e.g., when domaininformation does not readily provide a registration date). In someembodiments, determining the maturity of a domain also includesidentifying the domain as either a mature domain or an immature domain.For example, all contributing domains that were registered more than ayear ago may be identified as mature domains.

In some embodiments, a domain's rank is calculated based in part on onlymature contributing domains that are associated with the domain. Forexample, suppose a target domain called ClickHereForSearch.com is linkedto by four other domains, Yahoo.com, MSN.com, CNN.com, andSearchesRus.com. Suppose further that the first three domains have beenregistered for more than one year while SearchesRus.com is a new domainthat was registered less than two months ago. If, in the presentexample, a mature domain is defined as a domain that has been registeredfor more than a year without being expired or swapped, the domains,Yahoo.com, MSN.com, and CNN.com, would be identified as mature domainswhile SearchesRus.com would not. A rank for ClickHereForSearch.com maythen be calculated based on linking from Yahoo.com, MSN.com, and CNN.comonly (i.e., the mature domains) because SearchesRus.com is not a maturedomain.

In other embodiments, a domain's rank may be calculated based, at leastin part, on the presence of both mature and immature contributingdomains. In such embodiments, the contribution of immature domains to atarget domain's rank would be based only on the rank that the immaturecontributing domains received from mature domains associated with theimmature contributing domains. Such embodiments recognize that althoughnew domains often tend to be spam, not all new domains are spam andthat, in fact, there are typically new domains that provide greatutility. These embodiments assure that immature domains that quicklygather popularity for their utility are allowed to contribute rank thatis accumulated from mature domains associated with the immature domains.

Referring back to ClickHereForSearch.com example, suppose thatSearchesRus.com is a new domain that quickly gathered many other domainowners' attention for its unique search algorithms. Suppose further thatpopular and/or trusted domains (i.e., mature domains), such as ABC.com,Harvard.edu, and USPS.com, include at least one link to SearchesRus.comin addition to a slew of other new domains. In the present embodiment, arank for ClickHereForSearch.com may be calculated based not only on thecontribution from the mature domains, Yahoo.com, MSN.com, and CNN.com,but also on a rank of SearchesRus.com, which was calculated based onlyon ranks of its mature contributing domains, ABC.com, Harvard.edu, andUSPS.com.

In further embodiments, instead of identifying each contributing domainas either a mature or immature domain to determine its contribution to atarget domain's rank, each contributing domain's maturity (e.g., the ageof each contributing domain) may be used to determine the extent of thecontributing domain's contribution to the target domain's rank. In otherwords, a target domain's rank may be calculated based in part on afraction of ranks of contributing domains associated with the domain.The fraction of each contributing domain's rank used to determine thetarget domain's rank corresponds to the maturity (e.g., age) of thecontributing domain. For example, in an embodiment, domains that havebeen registered for more than ten years may contribute 100% of theiraccumulated ranks to a target domain's rank; domains that have beenregistered from six to ten years may contribute 75% of their accumulatedranks to a target domain's rank; domains that have been registered fromthree to six years may contribute 50% of their accumulated ranks to atarget domain's rank; domains that have been registered for one to threeyears may contribute 25% of their accumulated ranks to a target domain'srank; and domains that have been registered for less than one year mayonly contribute 10% of their accumulated ranks.

Referring again to ClickHereForSearch.com example, suppose thatYahoo.com has been registered for more than ten years; CNN.com has beenregistered for seven years; MSN.com has been registered for four years;and SearchesRus.com has been registered for less than one year. The rankfor ClickHereForSearch.com may be calculated based on 100% of theaccumulated rank for Yahoo.com, 75% of the accumulated rank for CNN.com,50% of the accumulated rank for MSN.com, and 10% of the accumulated rankfor SearchesRus.com.

Exemplary Methods

FIG. 4 is a flow diagram illustrating a method 400 for ranking a domainin accordance with an embodiment of the present invention. At block 402,contributing domains associated with a target domain are determined.Typically, the contributing domains are a set of domains that includeone or more links to the target domain. As indicated above, in someembodiments, the search engine 208 periodically crawls the sourcedevices, such as the source device 204, and collects new domaininformation and updates existing domain information. Such informationmay be used to identify contributing domains associated with the targetdomain.

At block 404, the maturity for each of the contributing domainsassociated with the target domain is determined. In general, a maturityof a domain is determined based on how long the domain has been known toexist. Typically, a maturity of a domain is determined based on the datethat the domain was registered or the date that the domain was firstdiscovered by a search engine (e.g., if the registration date cannot beascertained).

As indicated above, in some embodiments, one or more of the contributingdomains are identified as mature domains based on the maturity of thecontributing domains. For example, all domains that were registered morethan a year ago may be defined as mature domains. Similarly, in someembodiments, one or more of the contributing domains are determined tobe immature domains based on the maturity of the contributing domains.For example, all domains that were registered or discovered for thefirst time by a search engine less than a year ago may be determined tobe immature. In some embodiments, a maturity of a domain is reset if thedomain expires or if the domain is swapped. Domain registration istypically based on year-to-year basis. Domain owners are required to payan annual fee for keeping their domains. Domains will expire if theannual fees are not paid. Expired domains can, thereafter, be purchasedby different owners. Spammers may purchase a block of domains that havebeen expired as well as new domains to form a Web Farm. Domain swappingoccurs when domain users trade their domains. Spammers may takeadvantage of swapping by swapping their domains for domains that havenot been tainted. Spammers may be further prevented from escapingpreventive measures based on maturity of domains by resetting thematurity of the domains that have expired or have been swapped.

At block 406, a rank for the target domain is calculated. As indicatedabove, in some embodiments, only mature contributing domains are used tocalculate the rank for the target domain. In other words, onlycontributing domains that have been identified as mature domains bymeeting a predetermined minimum period of existence may contribute tothe rank of the target domain. For example, suppose that a spammerpurchases one hundred domains and has each of the one hundred domainsinclude links to the remaining ninety nine domains. This extensiveinterlinking would typically afford each of the one hundred domains apotential to receive a high rank based on the number of domains thatinclude a link thereto even though all one hundred of the domains may beless than a month old. However, the present embodiment prevents thesecontributing domains that have not been registered for more than aminimum period of time to qualify as mature domains. Accordingly, by notqualifying as mature domains in some embodiments, each of the onehundred spam domains may be successfully stopped from contributing ranksto the remaining ninety nine spam domain accumulating ranks.

In other embodiments, the target domain's rank may be determined basedon both mature contributing domains and immature contributing domains.However, in such embodiment, immature contributing domains contribute tothe target domain's rank only to the extent that the immaturecontributing domains have received rank from mature domains associatedwith the immature domains. For example, suppose that a mature domain isdefined as a domain that has been registered for more than six monthswithout being expired or swapped and that a target domain calledChildrensWorld.com is linked to by two other domains, ToysRus.com andNewToyCompany.com. NewToyCompany.com is a new domain that was registeredless than a month ago, but is linked to by two mature domains, Kmart.comand Target.com, in addition to other newer domains. A rank for thetarget domain may be calculated based on a rank of NewToyCompany.com,which was calculated based only on ranks of the two mature contributingdomains, Kmart.com and Target.com, in addition to the rank ofToysRus.com, which is a mature domain.

In further embodiments, the target domain's rank is determined not byidentifying mature and immature contributing domains, but by determiningthe extent of a contributing domain's contribution based on itsmaturity. Such embodiments provide a sliding scale approach based oncontributing domain maturity. In such embodiments, a fraction may bedetermined for each contributing domain based on its maturity andapplied to determine that respective contributing domain's contributionto the target domain's rank. For example, contributing domains that havebeen registered for a longer period of time (i.e., have a greatermaturity) may contribute more to a target domain's rank thancontributing domains that have been registered for a shorter period oftime (i.e., have a lesser maturity).

FIG. 5 is a flow diagram illustrating a method 500 for presenting searchresults in accordance with an embodiment of the present invention. Atblock 502, a search query is received at a search engine, such as thesearch engine 208 of FIG. 2, from a client device, such as the clientdevice 202 of FIG. 2. At block 504, one or more search results aredetermined for the search query using domains that have been previouslyreceived or collected and stored in a database, such as the database 308of FIG. 3. For example, the search engine may search the database andselect one or more domains stored therein that match the search query.

At block 506, a search results user interface is generated using domainrankings to determine an order for the search results. For example, thesearch results may be presented with the higher ranked domains at thetop such that users would see more reliable and/or popular domainsfirst. Typically, ranks for the domains have already been determined andstored in the database prior to being used for ordering the searchresults. The domain rankings may have been generated in a manner similarto the embodiments described hereinabove with reference to FIG. 4. Thesearch result user interface is then communicated from the search engineto the client device for presentation on the client device, as shown atblock 508. Advantageously, the present invention's approaches to rankingdomains may be used to assist search engines to rank domains inaccordance with the popularity and utility of the domains whilepreventing spam domains from earning undeservedly high ranks.

CONCLUSION

Embodiments of the present invention relate to, among other things,ranking a domain. One or more contributing domains associated with atarget domain are identified and the maturity of the contributingdomains is determined. By way of example only and not limitation, thematurity of a contributing domain may be determined based on the datethat it was registered or the date that it was first discovered by asearch engine. In turn, the maturity of the contributing domains may beused to calculate a rank for the target domain.

The present invention has been described in relation to particularembodiments, which are intended in all respects to be illustrativerather than restrictive. Alternative embodiments will become apparent tothose of ordinary skill in the art to which the present inventionpertains without departing from its scope.

From the foregoing, it will be seen that this invention is one welladapted to attain all the ends and objects set forth above, togetherwith other advantages which are obvious and inherent to the system andmethod. It will be understood that certain features and subcombinationsare of utility and may be employed without reference to other featuresand subcombinations. This is contemplated by and is within the scope ofthe claims.

1. A method for ranking a domain, the method comprising: receiving alist of one or more contributing domains associated with the domain;determining a maturity for at least one of the one or more contributingdomains; and calculating a rank for the domain based at least in part onthe maturity for the at least one of the one or more contributingdomains.
 2. The method of claim 1, wherein determining the maturity forat least one of the one or more contributing domains comprisesidentifying at least one of the one or more contributing domains as amature domain.
 3. The method of claim 2, wherein the mature domain isidentified based on factors comprising at least one of a date of domainregistration and a date of first discovery of the mature domain.
 4. Themethod of claim 3, wherein the mature domain is a contributing domainthat has been registered for more than one year without having expiredor being swapped.
 5. The method of claim 2, wherein calculating the rankfor the domain comprises calculating the rank based at least in part ona rank of the mature domain.
 6. The method of claim 1, whereindetermining the maturity for at least one of the one or morecontributing domains comprises identifying at least one of the one ormore contributing domains as an immature domain; and wherein calculatingthe rank for the domain comprises calculating the rank based at least inpart on a rank of the immature domain, wherein the rank of the immaturedomain is based on contributing domains associated with the immaturedomain that have been identified as mature domains.
 7. The method ofclaim 1, wherein calculating the rank for the domain comprisescalculating the rank based on a fraction of a number associated with atleast one of the one or more contributing domains, wherein the fractionof the number associated with the at least one of the one or morecontributing domains corresponds to the maturity of the at least one ofthe one or more contributing domains.
 8. The method of claim 1, whereineach of the one or more contributing domains comprise a domain thatincludes at least one link to the domain.
 9. The method of claim 1,further comprising using the rank of the domain to facilitate orderingresults for a search query that include the domain.
 10. A method forpresenting search results, the method comprising: receiving informationassociated with a plurality of domains; determining a maturity for eachof one or more contributing domains associated with each of theplurality of domains; calculating a rank for each of the plurality ofdomains based at least in part on the maturity for at least one of theone or more contributing domains associated with the each of theplurality of domains; in response to receiving a search query,generating one or more search results comprising at least one of theplurality of domains that match the search query; and presenting the oneor more search results in accordance with ranks of the at least one ofthe plurality of domains that match the search query.
 11. The method ofclaim 10, wherein determining the maturity for each of the one or morecontributing domains associated with each of the plurality of domainscomprises identifying at least one of the one or more contributingdomains as a mature domain.
 12. The method of claim 11, whereincalculating the rank for each of the plurality of domains comprisescalculating the rank based at least in part on a rank of the maturedomain.
 13. The method of claim 11, wherein determining the maturity foreach of the one or more contributing domains associated with each of theplurality of domains comprises identifying at least one of the one ormore contributing domains as an immature domain; and wherein calculatingthe rank for each of the plurality of domains comprises calculating therank based at least in part on a rank of the mature domain and a rank ofthe immature domain, wherein the rank of the immature domain is basedonly on contributing domains associated with the immature domain thathave been identified as mature domains.
 14. The method of claim 10,wherein calculating the rank for each of the plurality of domainscomprises calculating the rank based on a fraction of a rank associatedwith at least one of the one or more contributing domains, wherein thefraction of the rank associated with the at least one of the one or morecontributing domains corresponds to the maturity of the at least one ofthe one or more contributing domains.
 15. A search engine for rankingsearch results, the search engine comprising: a ranking componentconfigured to determine one or more contributing domains associated witheach of a plurality of domains, to determine a maturity for each of theone or more contributing domains, and to calculate a rank for each ofthe plurality of domains based at least in part on the maturity for atleast one of the one or more contributing domains; and a searchingcomponent configured to perform a search in response to a search queryand to return one or more search results comprising at least one of theplurality of domains that match the search query.
 16. The search engineof claim 15, further comprising a user interface component configured toreceive the search query and to present the one or more search resultsin accordance with the ranks of the at least one of the plurality ofdomains that match the search query.
 17. The search engine of claim 15,wherein the ranking component is further configured to determine thematurity for each of the one or more contributing domains by identifyingat least one of the one or more contributing domains as a mature domain.18. The search engine of claim 17, wherein the ranking component isfurther configured to calculate the rank for each of the plurality ofdomains based at least in part on a rank of the mature domain.
 19. Thesearch engine of claim 17, wherein the ranking component is furtherconfigured to determine the maturity for each of the one or morecontributing domains by identifying at least one of the one or morecontributing domains as an immature domain and to calculate the rank foreach of the plurality of domains based at least in part on a rank of themature domain and a rank of the immature domain, wherein the rank of theimmature domain is based only on contributing domains associated withthe immature domain that have been identified as mature domains.
 20. Thesearch engine of claim 15, wherein the ranking component is furtherconfigured to calculate the rank for each of the plurality of domainsbased on a fraction of a rank associated with at least one of the one ormore contributing domains, wherein the fraction of the rank associatedwith the at least one of the one or more contributing domainscorresponds to the maturity of the at least one of the one or morecontributing domains.